Chris Crawford Blast Analysis Meeting 2004/09/24 H(e,e’p) Analysis Chris Crawford Blast Analysis Meeting 2004/09/24

Outline elastic cuts background comparison of yields Helastic based on Dec out-bending Hcbc – wire chambers for April in-bending data Hpt – TOF elastic new timing offsets for Feb,April data background comparison of yields TOF only, WC AL,R, m GE/GM , PbPt projected errors

Hcbc – Wire Chambers [p,q,f,z]e, [p,q,f,z]p ) q,f,z (5 extras) pe:qe pp:qp qe:qp fe:fp ze:zp pmiss need better resolution (current re-crunch)

Timing Offsets flasher unstable for April runs retiming method refit flasher peaks aligned elastic timing peak in sets of 5k events overall relative offsets from cosmics use WC f to extract position offsets, slope

secondary peak

Hpt TOF elastic cuts cut on 48 TOF paddle combinations/side fit (ptr+ptl):(ttr-ttl) to 2-d gaussian elliptical cuts with parameter ns

Background Comparison # events/C Helastic Hcbc Hpt 2.4 3.2 5.5 7.6 7.7 7.9 2.2 2.9 4.8 7.1 6.9 7.5 3.8 5.0 1.4 .49 .20 .08 4.1 .21 .10 .46 .47 .54 .53 1.3 .30 .56 .59 .62 .73 1.5 2.7 .81 .26 .11 .03 1.6 2.3 .25 .08 .32 .29 .36 .52 .68 .65 .39 .35 .44 .62 .96 3.1 4.0 1.1 .36 .15 .07 2.9 3.3 1.0 .37 .16 .08

Yields Comparison TOF cuts only (lr ntuple) MC includes WC acceptance (see forward paddles)

Fit Method Super-ratio Method 2 equations in P, R i = left,right j = Q2 bin (1..n) b = spin angle Fit Method Super-ratio Method 2 equations in P, R for fixed bin j independent polarization in each bin! 2n parameters Pj, Rj Global Fit Method fit ALj, ARj to above formalism with P, Rj n+1 parameters n+2 (+spin angle?) same advantage as super-ratio method PbPt still cancels

Outbending Data (Dec)

Inbending Data(Feb, Apr)

Combined Datasets with Projected Errors based on additional 325kC of data 32% increase in density 3.2£ reduction in errors compared with 50kC in April